Patent GB-728000-A (GB)
Title: Improvements in or relating to power units consisting of at least one working cylinder and at least one compressor cylinder
IPC: F02G1/044
Filed: 1952-08-28
Abstract: 728,000. Free piston gas-generators. DROS, A. A. Aug. 28, 1952 [Oct. 17, 1951], No. 21663/52. Class 7(1). [Also in Groups XXVI and XXVIII] A power unit which may be a motor-compressor or a pressure-gas generator comprises at least one working cylinder with a piston therein and at least one compressor cylinder with a piston therein, the working piston or pistons being arranged to drive the compressor piston or pistons, the moving parts of the unit, which consist exclusively of reciprocating or oscillating parts, being subdivided into at least three mass systems, at least one of these mass systems being arranged to move at a frequency which is double that of two of the other systems, the lower or single frequency systems being arranged to move with a phase difference of 90 degrees between them and being coupled to one another by the double frequency mass system or systems, the working piston or pistons being part of the double frequency mass system or systems. A pressure-gas generator comprises four internal combustion engine cylinders 1-4 arranged in coaxial pairs and containing pistons 5, 6 connected through rods 8, 9 with arms 15, 16 projecting from a member 14 pivoted at 49 to toggle arms 51 which roll, with the assistance of intermeshing gear teeth, on vertical guides 54 so that the pivot 49 is constrained to move vertically. The member 14 has a second pair of arms 17, 18 which are pivoted at 19 to rocking levers 21, supported on stationary pivots 24, and are pivoted at 47 to connecting links 43-46 which drive rocking elements 39-42 respectively supported on stationary pivots 35-38. The elements 39-42 are connected through rods 31-34 respectively with double-acting compressor pistons such as 30 which are reciprocated at half the frequency of the working pistons. The single frequency elements 39, 42 move with a phase difference of 90 degrees and the elements 40, 41 also have a phase difference of 90 degrees. Each compressor cylinder supplies air through ducts 60, 61, 62 to a corresponding working cylinder from which the gaseous products of combustion are discharged through ducts 75, 76 and led to a gas turbine. The engine portion preferably operates on a four-stroke cycle but may alternately be operated on a two-stroke cycle. Inlet and exhaust valves in the ends of the working cylinders are operated by cam shafts 65, 66 driven through gears 67, 68, 71, 72 from the meshing elements 39-42. The member 14 forms a counterweight which together with a further counterweight 23 provided on the rocking lever 21 balances the inertia forces of the working pistons and also assists additional counterweights provided on the rocking elements 39-42 to balance the inertia forces of the compressor pistons. In other embodiments four vertical engine cylinders co-operate with two vertical compressor cylinders, and four horizontal engine cylinders each containing two opposed pistons co-operate with eight horizontal compressor cylinders. In both these embodiments the compressor pistons reciprocate at half the frequency of the working pistons.